(a) Field of the Invention
The present invention relates to a diagnosis device of a voltage transformer, and a method thereof.
(b) Description of the Related Art
A DC-DC converter is a voltage transformer that receives a DC voltage and outputs a DC voltage, and may be referred to as one of several types depending on usage.
For instance, a DC-DC converter may be an insulation type or a non-insulation type, depending on an insulation method. Also, a DC-DC converter may be a voltage drop type, a voltage boost type, or a voltage drop/boost type depending on a transformed voltage level.
A DC-DC converter may have a symmetric circuit that receives a regular level of DC voltage input and outputs a regular level of DC voltage, such that power transmission to the output terminal can be achieved by current transformation. A switch typically is disposed to regulate the current flowing, and the switch converts the current flowing direction by on/off operation to a forward direction or a reverse direction. If the current that flows in opposite directions through the on/off operation of the switch has the same transition shape, it is referred to as a DC-DC converter having a symmetric circuit structure. A DC-DC converter having the symmetric circuit structure typically includes a full bridge converter and a half bridge converter. This type of DC-DC converter outputs a symmetric current such that the current is not biased to one side and thereby the current offset value becomes “0”.
If the current does not form a symmetric line in such a DC-DC converter, then a current offset is formed, and in this case, a normal voltage cannot be outputted, and as a result, the operation thereof can be halted and the switch can be damaged.
Accordingly, it is important to design the converter such that the current offset is not formed by sustaining a symmetric current.
However, although a current offset may be formed due to a design or manufacturing problem, it is difficult to determine whether the current is symmetric or non-symmetric while it is operating.
Accordingly, if it is suspected that a current offset is formed, a separate measuring apparatus such as an oscilloscope used to measure a wave form can be connected to an output terminal of the DC-DC converter to measure the current of the converter, so as to determine whether a current offset is formed or not.
Accordingly, according to conventional technology, it is difficult to determine whether the DC-DC converter generates a current offset.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.